(1) Field of the Invention
The present invention relates to a method for isolating and identifying temporal fault events. More specifically, the present invention relates to a method of performing single fault isolation and detection in engine systems, and, if warranted, double fault isolation and detection.
(2) Description of Related Art
The goal of gas turbine performance diagnostics is to accurately detect, isolate and assess the changes in engine module performance, engine system malfunctions, and instrumentation problems from knowledge of measured parameters taken along the engine's gas path. Discernable shifts in engine speeds, temperatures, pressures, fuel flow, etc., provide the requisite information for determining the underlying shift in engine operation from a presumed reference (nominal) state. The aforementioned engine performance changes can manifest themselves in one of two categories: a) gradual (long-term) deterioration or b) rapid (short-term) deterioration.
Various techniques exist to detect the onset of short term, single fault conditions in a series of parameter measurements. Such short term anomalies are usually situated between periods of relative equilibrium during which long term degradation of engine or module components exhibit gradual deterioration. In addition, in rare instances, such short term anomalies are the result of double fault conditions involving the near simultaneous malfunctioning of two components. In order to accurately identify the cause of a single or double fault condition there is needed a method whereby measurement data recorded before, during, and after a fault condition is correctly identified as to its nature for use in subsequent fault identification. There is additionally needed a methodology whereby such measurement data may be analyzed to provide accurate identification of underlying fault conditions.